In the field of inked ribbons for printing operations, there have been various ways and means for inking the ribbon and for controlling the path or attitude of the ribbon in the area immediately prior to and past the print station. It is, of course, desired to have the ribbon track along a path whereby the ribbon is controlled in a precise manner, both laterally and vertically, in the area adjacent each side of and past the print station. In the past the tracking of an endless ribbon has been a problem unless extreme care was exercised in providing guide means for the ribbon in the nature of pins, posts, etc. and adjusting of same so as to provide and maintain a properly inked ribbon in a precise path to minimize "down time" of printing.
In some printing applications, the endless ribbon is contained in a cassette and includes a plurality of coils of the ribbon in an area adjacent an inking core member, the ribbon driven in a taut or tensioned manner from the plurality of coils thereof, past the print station, and back to the coils. In other printing applications, the endless ribbon is contained in a cassette of the stuffing box type, wherein the ribbon is pulled through an opening, guided past the print station, and then made to re-enter the cassette, the ribbon being stuffed or folded in an "uncontrolled" manner inside the cassette.
Representative prior art in the endless ribbon field is shown in British Patent No. 12,870, dated June 4, 1913, and issued to R. Burk, wherein an inking ribbon is driven by rollers from a printing station and into a container, the ribbon being loose therein and then taut at the exit of the container.
British Patent No. 29,235, dated Dec. 18, 1913, and issued to Stockall et al., discloses an ink ribbon mechanism wherein an endless ribbon is contained loose within a magazine and is driven by a feed roller and a friction roller, the ribbon being loose or slack in the area beyond the drive roller and tensioned or taut in the operating area around the guide rollers and the type wheels.
IBM Technical Disclosure Bulletin, Volume 7, No. 12, May 1965, Page 1212, shows an endless ribbon feed wound in turns around a pair of bobbins and directed by various pin or bar guides and lift guides past the printing station where the ribbon is kept in constant tension.
IBM Technical Disclosure Bulletin, Volume 13, No. 11, April 1971, page 3324, shows a reversible endless tape cassette having flanged wheels with a spring mounted to bear against the axles to maintain the edge of the flanges against portions of the case. A capstan pushes one of the wheels inward and drives the tape between the flanges of the wheel and a portion of the case.
IBM Technical Disclosure Bulletin, Volume 15, No. 2, July 1972, Page 543, shows an endless fold ribbon cartridge with drive rollers for driving the ribbon from an operating area into "sine wave shaped" folds downstream of the drive rollers.
U.S. Pat. No. 3,400,800 issued to N. McMillan et al. on Sept. 10, 1968, shows printing ribbon support apparatus including ribbon guide means wherein end pieces with ears each have a flange plate associated with ribbon mandrels to carry the ribbon past a printing station. A plate, a shim and a guide bar provide trough space for the ribbon, and an inner surface functions to guide the edge of the ribbon and to restrain it from moving laterally.
And, U.S. Pat. No. 3,814,231 issued to S. D. Cappotto on June 4, 1974 shows a stuffed ribbon cartridge having an endless ribbon loosely contained in the cartridge and movable by a feed roller and an idler roller along an arm for guiding the ribbon past a print point. A shroud is provided near the exit area of the ribbon cartridge to retain all but a single strand of ribbon from being fed from the cartridge.